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Fenix 7 GPS accuracy underbridge

Cerina
over 3 years ago

Hi,

while hiking through an under crossing I recognized a strange behavior of the GPS (see picture). I was using Fenix 7 Solar with firmware 7.35 and GPS 2.27 with all satellites activated in the hiking profile.

 

Has anyone any recommendations for me to avoid these “spikes” in the route while crossing tunnels or under crossings?

Greetings 

Sebastian

  • 0 over 3 years ago in reply to 2572376

    I know that many years, all of your hard earned lessons wroted in this tread, but.. why you spend 1000 eur for watch, that can't be better than 50 euros Amazfit in GPS positioning. Multi Sat and Multi frequency was invented only for commercial purposes? 

  • 0 over 3 years ago

    Not a lot of bridges yet with the F7, but so far it looks ok.



    But very similar to the F6:

  • 0 over 3 years ago in reply to Sylvo

    GPS doesnt work in tunnels. period. It needs a view of the sky to get a fix, thats pretty much common sense. Short tunnels you might get away with it, but long tunnels there will be no signal.
    It may be that the watch uses its accelerometers to estimate where it should be when it loses the signal, but thats down to individual hardware and doesnt really have a lot to do with the GPS hardware itself.

    Multi frequency is meant to be used where the signal is poor, weak, or confused, it isnt designed to give you a more precise location than the normal GPS, but it attempts to keep that precision when the signal quality drops.

    Multi sat is just a practical outcome of several regions of the world wanting their own GPS system independant of the USA.

    Each system biases the quality of its coverage based on which region it serves.

    The result is it just gives the GPS chip the option of many more GPS signals to chose from OR, a better choice of satelittes considering their position in the sky and the angual differences between each other.

    If you think the GPS is that bad then send the watch back. I have had a FR245, 645, F6XS and F7XSS and they all worked well for me, but the F7 certainly gives a more accurate track, but I am also pragmatic and I dont really care if I cant tell which side of the road I am on, its not interesting, and also not useful either. Like I said, a perfect signal reception gives you an error circle diameter of about 6 meters or about 20 feet.

  • 0 over 3 years ago in reply to 2572376

    Ok. One more time, but slowly. I know everything described. I work with GPS units maybe 20 years (from etrex model) and you want to force me that my 1000 eur GPS watch is only for approximately tracking and you don't need exact numbers from that watches. Mhmm, great

  • 0 over 3 years ago in reply to Sylvo

    for one last time, you do not get exact numbers from a GPS unit. You get an approximation with a circle of error, same for all GPS chips (without external augmentation).

    3 meter accuracy anywhere on the planet, and you still complain, you need to get a life.

    If the F7 doesnt work for you, send it back and quit moaning about it.

    Most of the cost of the Garmin watch isnt the GPS chip, thats a solid state mass produced part that is cheap to produce and just works.

    The cost is in all the software that is loaded onto the watch that most people only use 5-10% of for any use case.